A rare book dealer Dean Corso is hired by eminent book-lover and scholar of demonology, Boris Balkan to search for the last two volumes of the legendary manual of satanic invocation "The Nine Gates of the Shadow Kingdom". To complete this mission, Dean Corso has to travel through many countries and face a maze of pitfalls and temptations, but with the suppor of a powerful fore, he deals one by one and figures out the real purpose of his quest.